Draftsman&#39;s triangle



Patented Aug. 16, 1949 UNITED STATES vr'PA-*I 'ENT OFFICE j 2,479,092 DRAFTSMAS TR'IAGL Lydia G. aile's, Seattle, Wash; Application .lune 14, 1945, Serial Noi 599,44'i 1 Claim. (li .L-104) This invention relates to draftsmens equipment and has for its object to provide a triangle and slide rule combination.

Another object oi my invention is to provide a combined triangle, curve, square, slide rule, protractor and lettering device.

A further object of the invention is to provide a transparent triangle having longitudinal pockets therein for irictionally carrying opaque slidable rules.

A still further object of the invention is to provide a triangle provided with a diagram of pencil point apertures for letter forming.

One purpose of this invention is to provide in a triangle means whereby circles of various diameters may be scribed.

An object of the invention is also to provide a slide rule triangle in combination with a casing for a series of rules to be used in connection therewith.

Other features and advantages will become more readily apparent from the following description and the accompanying illustrative drawings in which:

Figure l is a plan View of my drawing instrument,

Figure 2 is a detail plan view of a ruler used with the device,

Figure 3 is a similar View of another ruler,

Figure 4 is an end view of a ruler case, the top being removed, and

Figure 5 is an elevation thereof, the top being shown separated therefrom.

Figure 6 is a section taken on line 6-6 of Figure l.

In the accompanying drawings as above enumerated and in the following specication, like characters of reference indicate like parts throughout and in which I0 denotes my invention which consists of a triangle I| formed of i any suitable transparent material. In the shorter edges I2 and I3 of the triangle I provide elongated recesses |4 and I5 within which are frictionally held rulers I6 and |1. These recesses extend entirely through the triangle in order that the rulers may be used from either of the ends I8, I9, 2|! or 2| thereof.

A cut-out 22 is provided in the apex portion 23 of the triangle and the arcuate edge 24 of a protractor 25 extends thereinto. is also provided in the body portion 21 of the triangle whereby various curves may be scribed therewith. In the end 28 of said body I provideV a series of groups 29, 30, 3|, 32 and 33 of pencil point apertures, which together form a diagram A curve cut-out 26 t from which lettering may be laid out, and the said groups are appropriately` denoted by refer; ences 34, 3'5, etc. The ruler I6 has an inchscale 36 on one side and another desirable scale Orl its reverse side (not shown). The ruler |1 is provided with a twenty fraction scale 31 on one side and an appropriate scale on its reverse side (not shown). The scales 36 and 31 are (and the rulers themselves may be) opaque, in order that they may be clearly seen through the walls 38 and 39 of said recesses.

As a number of rulers having various scales indicated thereon, I provide in combination with my triangle, a case 4|) having a series of slots 4|, 42, etc., within which the rulers may be kept when not in use. There is a friction cap 43 for the case.

It is to be noted that I provide scales 44 and 45, adjacent the margins 4B and 41, of the triangle which are to be used in combination with scales on the rulers for slide rule purposes. It is also to be noted that I provide a series of pencil point apertures 48 and 49 along the marginal edge 50 of the long straight edge 5| of the device, into any one of which a push pin (not shown) may be inserted to pivot the triangle to a drawing board and into any one of the apertures 49, 30, 3| or 32 a pencil point may be projected through means of which a very large variety of circles, arcs, undulations, waves, spirals, threads, etc., may be plotted.

It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after considering the description in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in shape, size and rearrangement of details and parts such as come within the purview of the invention claimed may be resorted to, in actual practice, if desired.

Having now described my invention, that which I claim as new and desire to procure by Letters Patent is:

A drafting instrument comprising a at triangular body portion, longitudinal slots through the shorter legs of said triangular body portion sub- ,stantially parallel to the straight edges thereof,

said slots being open at the ends only, scales removably secured in said slots and opaque indicia on said scales, said slots joining at the intersection of the shorter legs of said body portion and extending completely through each other, whereby said scales may be removed from each end of said slots, the scales being secured in said slots bythe frictional engagement of the sides thereof with Number the bore of said slots. 1,101,119 LYDIA G. BAILES. 1,156,512 1,171,329 REFERENCES CITED 5 1,704,540 The following references are of record in the le of th1s patent. 1;995:204 UNITED STATES PATENTS 2,336,393

Number N me Date 10 a 893,085 Loughborough July 14, 1908 4 Name Date Classon June 23, 1914 Allyn Oct. 12, 1915 Early Feb. 8, 1916 Keutel Mar. 5, 1929 Sanden Apr. 15, 1930 Wellington July 3, 1934 Ford Mar. 19, 1935 Combes Dec. 7, 1943 

